P4069 EM Microelectronic, P4069 Datasheet - Page 8

• Manufacturer Part Number: P4069
• Description: 128 Bit Read/write Contactless Identification Device With Otp Function
• Manufacturer: EM Microelectronic

Command 4 : Write configuration word
Command 4 has the same structure as command 3.
The 16-bit configuration word is written by this
command. A partial locking (write inhibit) of the 128
bit memory is possible in blocks of 16 bits (16 bit
word becomes read-only).
The bits of configuration word are OTP (one time
programmable) so once a certain bit in configuration
word is set it cannot be reset.
Command 5 : Read configuration word
Read configuration word command is an auxiliary
command used to read configuration word. This
mode will be active until power down or reset
command.
The 8-bit CRC with polynomial u
is used in commands 3 and 4. The CRC is calculated
including the Command-Byte.
The following table shows the CRC according to
some test bytes:
In test above it is supposed that the leftmost bit is the
MSB and is transmitted first.
Within 1ms after EEPROM update completion, a
further command will be accepted by the P4069
without a new synchronization pattern.
After time-out of this period, the P4069 will return to
read out mode.
CRC Calculation
MSB
7 6
+ Exclusive OR
Register Stage
U
2
+
Byte
[hex]
01
80
EM MICROELECTRONIC-MARIN SA
5
U
3
+
4
Resulting CRC
U
4
+
[hex]
1D
26
8
3 2 1 0
+ u
Table 6
4
+ u
LSB
3
U
+ u
Figure 9
Data
8
+
2
+ u
0
Write 16 bit EEPROM Word Command
As described in the Command Table an 8-bit pattern
has to be sent to execute commands rst, rROM and
rcw. Bit pattern of Write Word command is different
since word address, 16 bits of data and 8 bit CRC
have to be transmitted. The Write command bit
pattern is the following:
1100 [4 bit word address] [16 bit data] [8 bit CRC]
Word address:
One of eight EEPROM words is selected. Valid
addresses are in range from 0 (0000) to 7 (0111)
Data bits:
During read out bit which is first sent in is first read
out (FIFO)
CRC:
Calculated over whole command stream
Example of Write Word command:
C5 D2 2D 20 (hex)
The above command (1100 0101) write to
•
•
•
Write Configuration word Command
Configuration word is a special word which is used to
lock (protect from writing) EEPROM words. The bits
of configuration word are OTP (once programmed at
1 they can not be reprogrammed to 0).
Special care has to be taken when adding lock
bits to the protection word that already has some
bits set to one. The bits that are already set to
one have to be confirmed at a new command in
order to allow writing of additional bits. If not,
bits that are already locked stay locked, and the
new selected bits might not be programmed (see
example below).
out Read
in
Word 5
hexadecimal data “D2 2D”
CRC bits are hex 20.
Sync.
wr
P4069/P4169
t
Wee
1ms
Figure 10
Read
8